Reza Rezaee; Ghasem Hasani; Seyed Edris Salehi
Abstract
Introduction: Apple is a major commercial fruit crop grown in Iran. The country produces approximately 1.6 - 2.7 million tonnes of apples and was one of the top 10 apple producing countries in the world during the last decade. West Azerbaijan province, with more than 50,000 hectare of apple orchards ...
Read More
Introduction: Apple is a major commercial fruit crop grown in Iran. The country produces approximately 1.6 - 2.7 million tonnes of apples and was one of the top 10 apple producing countries in the world during the last decade. West Azerbaijan province, with more than 50,000 hectare of apple orchards and by producing of approximately one million tonne of fresh apple, is one of the main regions of apple production in Iran. In this region, two common apple cultivars Red Delicious and Golden Delicious are dominant (>90%), which needs to be updated by new apple cultivars to satisfy different technical/management as well as worldwide marketing requirements. Apple cultivars evaluations was started in Iran since 1953 and a lot of apple collection were established, but and until new apple cultivar was not introduced to farmers, As a first step for introduction of alternative cultivars, in this study, vegetative growth, flowering time, fruit ripening time as well as fruit quality of 12 apple (Malus pumilla Mill) cultivars were evaluated under Urmia climatic conditions. Therefore, the main objective of this study was to evaluate vegetative growth, quality and compatibility of some apple cultivars to allow selection of alternative cultivars for commercial apple production in the northwest province of Iran.
Materials and methods: This experiment was conducted at the Kahriz Horticultural Research Station located in Urmia-Iran (latitude 44°07' E; 37º 53' N.; altitude, 1325 m above sea level). The experimental design was randomized complete blocks, with 12 treatments (cultivars) and three replications. The apple cultivars including Golden Delicious, Red Delicious, Red Spur, Fuji, Delbar Stival, Golden Smothee, Jonagold, Gholab-Kohanz, Golab-Kermanshah, Mahali Shikhi and Shafie Abadi were grafted on MM 111 rootstock. Trees were 10-year-old with a planting distance of 3 x 4 m and were trained as modified leader system. Data collected for annual shoot growth, time of blooming as well as fruit quality traits for one growth season and all data obtained from the trial were analysed using combined ANOVA and means were compared using the Duncan's Multiple Range Test (DMRT). SPSS (version 20) was used to analyse the data.
Results and Discussion: Analysis of variance showed that apple cultivars were significantly different for all traits. Based on the means comparison test, the most and least annual shoot growth was observed in Red Delicious and Red Spur with 51.80 and 26.23 cm, respectively. The studied apple cultivars were ranked in three and five groups in terms of flowering and fruit ripening time, respectively. Flowering time is important for breeding as well as pollination purposes and in this regard there were significant differences among cultivars. The highest and the lowest fruit weight 236.07 and 63.28 g was obtained from Red Delicious and Mahale Sheikhi, respectively. The highest fruit firmness was observed in Fuji (9.17), followed by Golab Kermanshah (9.13), Red Delicious (9.03) and Golden Delicious (8.76). The highest (18.6%) TSS was observed in Fuji cultivar followed by Red Delicious (17.00%), and the lowest TSS was observed in all of early ripening cultivars. Titratable acidity (TA) was also significantly different among cultivars with Fuji showing the highest (1.32) and Golab Kermanshah, Golab Kohanz and Golshahi were the lowest (0.31-0.44) values. Compared to the other cultivars, Red Spur and Jonagold with a more L/D ratio (0.91) showed an elongated fruit form. Fruit shape especially the ratio of L/D has an important role in marketing. In addition, due to low growth and dense canopy as well as good fruit quality, the two recent cultivars are recommended for high density planting.
Conclusion: Final ranking of cultivars based on cumulative ranks from different traits showed that the higher ranks for Fuji, Red Spur and Goden Smothee, indicating their higher potential as an alternative to the Red and Golden delicious. Among the evaluated cultivars, three cultivars including Jonagold, Golshahi and Delbar Stivel were the best option to fulfill market demands for fresh fruit during mid-summer trough early autumn. It should be emphasized that these cultivars may be suitable for similar climates, but because of the effects of growing conditions (i.e. soil type, climate, cultural practices etc.) on the results of cultivar evaluation projects, complementary trials should be done in other regions before commercial planting commences. Continuous evaluation of new apple cultivars is an important prerequisite for sustainable apple industry.
Reza Rezaee; Faranak Naghilou
Abstract
Introduction: Persian walnut (Juglans regia L.) is an important nut crop in Iran and many parts of the world. One of the major challenges of growing walnut is planting of non-grafted walnut trees in orchards, which leads to the reduction of yield, quality and productivity of walnut orchards. Compared ...
Read More
Introduction: Persian walnut (Juglans regia L.) is an important nut crop in Iran and many parts of the world. One of the major challenges of growing walnut is planting of non-grafted walnut trees in orchards, which leads to the reduction of yield, quality and productivity of walnut orchards. Compared to the other fruit trees, walnut grafting is difficult and even newly grafted walnut seedlings are vulnerable to fall or winter frost chilling, so that most of the seedlings are lost after subjecting to the cold winter. There are a few studies reporting successful grafting in outdoor conditions, however, final grafting take after winter has been usually ignored. Hence, increased walnut grafting success and improved tree growth after grafting through foliar nutrient application may lead to increased tolerance of chilling. Therefore, main goals of this research were to investigate the effect of some graft covers and role of foliar spray of calcium, boron and zinc on the reduction of frost damage in newly grafted seedlings under outdoor conditions.
Materials and methods: This research was conducted at agricultural research station, Khoy city, west Azerbaijan province, during 2012-2014. In the first experiment, three methods of grafting including cleft, bark and V-shaped, and two kinds of graft covers including moist sawdust and superabsorbent plus cotton wool were investigated in terms of grafting success and quality of seedlings. In the second experiment, effect of the three above-mentioned grafting methods and two levels of foliar spray including sequential spray of Ca (4 ppm), B and Zn (2%) (3 times during growth season) and control (no spray) were studied in terms of frost damage. The experiments conducted in factorial based on randomized complete block design with 10 trees in each plot. Data were collected 45 days after grafting take, final grafting take after one winter, subsequent scion growth length and diameter and concentration of Ca, B and Zn in the tissues of shoot tips as well as percentage of frost damage one year after grafting. The collected data were transformed by relevant methods and analyzed by GLM analysis using SPSS software.
Results and discussion: According to the results obtained from the first experiment, significant differences were observed among grafting methods and grafting covers in terms of grafting success and scion growth. Cleft grafting with the grafting take of 47.4% after 45 days was ranked as the best method, followed by bark and V-shaped grafting methods with 40.0 and 35.0 %, respectively. Meanwhile, V-shaped grafting method finally showed the highest grafting take with 46.6%. The effect of grafting type was also significant for scion shoot length and diameter, with the highest scion growth obtaining from bark grafting method. Regarding the effect of cover types, significant differences were found between the two types of covers, so that the highest grafting take (75.5%) obtained from moist sawdust cover compared to the lowest grafting take (11.1%) from super absorbent plus cotton wool cover. The increase found in grafting success by sawdust cover was in agreement with the previous reports. This increase can be attributed to the buffering action of sawdust in absorbing xylem sap, provision of moist and aerated conditions suitable for better callus formation and subsequent scion growth without any wood rot symptoms around the graft area. The results of the second part of the research also revealed that percentage of frost to dieback of shoots varied statistically among the three grafting methods. The lowest frost damage (17.5%) was related to the cleft followed by V-shaped grafting method (20.0%). The highest frost damage (24.6%) was observed on scion woods grafted by bark grafting method. Results related to foliar spray showed that spray of Ca, B and Zn caused a significant reduction in frost damage percentage. In the sprayed plots, the average of frost damage was only 11.6% compared to the control plot with the damage rate of 29.4%. Moreover, foliar spray statistically increased the concentration of related elements in vegetative tissues of scion.
Conclusion: Based on the results, using V-shaped, cleft and bark grating methods covered with moist sawdust were effective for the increase of graft success percentage. Spraying of young grafted trees with Ca, B and Zn was also effective to reduce frost damage and is thus recommended in walnut nurseries. Moreover, there was a significant interaction between grafting method and spraying treatments in terms of balanced scion growth and higher contents of mineral in scion tissues, indicating that choosing an appropriate method of grafting and spraying can be effective in the reduction of frost damage. In this study, the lowest frost injury was observed with cleft grafting and spraying treatments due to relatively reduced scion growth as well as higher content of minerals in scion tissues.
